Design Of New Blood Cell Analyzer Detection System

Hematology analyzer whose detection parameters are important basis when judging the type of disease is one of the most commonly used equipment for clinical diagnostics. Compared with imported equipment, domestic equipment quality still has much room for improvement for the development of domestic research started late, while scientific research is behind of developed countries. In the 21st century, analyzer technology has become a hot research and application because state has increasing investment in research on medical facilities.The count is very difficult for the platelet cell is the smallest of all kinds of cells. The systems can detect the signal of blood platelet and akaryote, identify the different signal and analyze the noise situation using blank test automatically. The system detection is based on electrical impedance spectroscopy. For collecting and processing the cell signaling, this paper presented the design of low noise constant current source as reference signal, and the design of the analog circuit including differential amplification, the threshold comparison, phase modulation, filtering processing, modulus conversion, etc. Use the AD converter chip to convert the pulse voltage, at the meantime use the high speed collecting circuit based on FPGA to collect and pre-processing these data. Design the control circuit based on STM32F207 for processing theses data which has been pre-processed, and story them in expand memory chip SRAM, and the detection system is extension with CAN bus, it can communicate with auxiliary system easily. The microprocessor transplant is based on real-time operating system RT-Thread, the design has increased the detection efficiency due to effective coordination mechanism for each task detection process. Host computer control module programmed by C#, testing and debugging becoming more convenient and quicker by configuring and using USB port. The system can detect the platelet to analyze the state of cell, reduce detection error by compensation algorithm, achieve the optimum counting program by curve fitting. Finally, use the system to detect a whole blood sample, by comparing the test results with quality control target value, verified the test results meet the requirement of accuracy and repeatability.